CAPRIMULaiD^ — THE GOATSUCKERS. 403 



In some of the peculiarities of its breeding the Mosquito-Hawk displays 

 several very marked variations of habit from the Whippoorwill. While 

 the latter always dej)osits its eggs under the cover of shady trees and in 

 thick woods, these birds select an open rock, a barren heath, or an exposed 

 hillside for their breeding-place. This is not unfrequently in wild spots in the 

 vicinity of a wood, but is always open to the sun. I have even known the 

 eggs carelessly dropped on the bare ground in a corner of a potato-field, and 

 have found the female sitting on her eggs in all the bright glare of a noon- 

 day sun in June, and to all appearance undisturbed by its brilliance. A 

 more common situation for the eggs is a slight hollow of a bare rock, the 

 dark weather-beaten shades of which, with its brown and slate-colored 

 mosses and lichens, resembling both the parent and the egg in their color- 

 ing, are well adapted to screen them from observation or detection. 



The great abundance of insect life of certain kinds in the vicinity of our 

 large cities has of late years attracted these birds. Each summer their 

 number in Boston has perceptibly increased, and through June and July, 

 at almost all hours of the day, most especially in the afternoon, they may 

 be seen or heard sailing high in the air over its crowded streets. The 

 modern style of house-building, with flat Mansard roofs, has also added to 

 the inducements, affording safe and convenient shelter to the birds at night, 

 and serving also for the deposition of their eggs. In quite a number of in- 

 stances in the summers of 1870 and 1871 tliey were known to lay their 

 eggs and to rear their young on the flat roofs of houses in the southern and 

 western sections of the city. I have also been informed by the late Mr. 

 Turnbull, of Philadelphia^ that the flat roofs of large warehouses near the 

 river in that city are made similar use of. 



If approached when sitting on her eggs, the female will suffer herself to 

 be almost trodden on before she will leave them, and when she does it is 

 only to tumble at the feet of the intruder and endeavor to draw him away 

 from her treasures by well-feigned lameness and pretended disability. Her 

 imitation of a wounded bird is so perfect as to deceive almost any one not 

 aware of her cunning devices. 



The eggs of this bird are always two in number, elliptical in shape, 

 and equally obtuse at either end. They exliibit marked variations in size, 

 in ground-color, and in the shades and number of their markings. In cer- 

 tain characteristics and in their general effect they are alike, and all resem- 

 ble oblong-oval dark-colored pebble-stones. Their safety in the exposed 

 positions in which they are laid is increased by this resemblance to the 

 stones among which they lie. They vary in length from 1.30 to 1.13 inches, 

 and in breadth from .84 to .94 of an inch. Their ground is of various 

 shades of stone-color, in some of a dirty white, in others with a tinge of 

 yellow or blue, and in yet others a clay-color. The markings are more or 

 less diffused over the entire egg, and difler more or less with each specimen, 

 the prevailing colors being varying shades of slate and of yellowish-brown. 



